Long Flights & Deep Vein Thrombosis

Discussion in 'Articles' started by The Hunt Doctors, Oct 15, 2009.

  1. The Hunt Doctors

    The Hunt Doctors AH Member

    Mar 5, 2008
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    Long Flights & Deep Vein Thrombosis

    A few times each year the general public is bombarded with information about a new risk for a “new” disease. Usually the media blitz is the result of a celebrity type championing a cause or contracting an ailment. Often this blitz is much ado about nothing, other times it is a genuine warning. Recently, Mr. David Bloom, a well known reporter in Iraq, died from a blood clot which fatally traveled to his lungs and brought this relatively common condition to national headline news. Blood clots (thrombosis) are not new and their causes are fairly well defined. They are also common. It is estimated that 2 million thromboses occur per year in the U.S. which results in over 200,000 deaths. That is a huge number; more deaths (in the US) then occurs from AIDS, breast cancer and motor vehicle accidents all combined.

    Long periods of time in a seated position are a known risk of thrombosis; say like a trip to Africa. This reality set in when Paul was traveling to Zimbabwe. An announcement came on seeking the help of a physician and Paul responded to find a pregnant passenger with the rapid onset of shortness of breath. After his evaluation it was apparent that this woman had a blood clot in her leg break off and travel to her heart and from there it lodged in the vessels leading to her lungs. Luckily though, the clot was not a large one and was not immediately life threatening. Paul did his best with the minimal and we mean minimal medical equipment that the airlines carry on board with them. All he could do was keep her calm, still, and in a recumbent position which necessitated moving up to first class and displacing two unhappy passengers from their very comfy seats/beds.

    Just a brief word here about medical care options on an airplane. That word is don’t get sick. There is virtually no equipment of any real utility on board. What is available other than oxygen won’t help unless you’re not all that sick. The most concerning thing was that the pilot actually came down and informed Paul that he would need at least two hours advanced notice if he thought the patient was going to deteriorate to the point of requiring an immediate landing to obtain emergency medical care. It’s a big world after all if you’re in the middle of the ocean. Absent diagnostic equipment and treatment options, he had no idea if or when she was going to deteriorate any further. The bottom line was that there was actually very little that could have been done. We tell you this story to point out how fast this problem can put you in dire straights. Luckily, she remained stable and was off loaded on the Isle de Sol on the way to Jo’burg.

    There are many medical conditions that can place you at an increased risk of a thrombosis. These include relatively rare inherited conditions, cancers, heart failure, recent surgeries, a history of surgery or injuries to the legs, extreme obesity, tobacco use, advanced age, previous clots and pregnancy. Estrogen, particularly as found in birth control pills is another well documented risk enhancer. As you can see a blood clot can form for many reasons.

    By far the main risk for the average person to develop a thrombosis is prolonged stationary sitting in which the lower extremities are in a dependent position (i.e. hanging down much lower then the level of your heart). Reduced rate of blood flow is the common denominator. Sitting with legs bent at the knee, and sitting still can obviously retard blood flow in the veins of the legs. Long distance driving and long plane flights are the ideal set-up for clot formation and the most common cause of DVT’s in the general public. Keep in mind that two million events per year number and avoid being the other guy who gets sick on their trip.

    Before our usual focus on prevention, we thought more information would be helpful. Blood clots are classified into two types; superficial and deep. The superficial variety (aka superficial phlebitis) is a clot in a smaller surface vein. It is usually readily apparent to the afflicted. A superficial vein is now red and painful. This condition does not posses the life threatening potential of the deep vein thrombosis (DVT).

    The DVT is a physically larger clot, in a large caliber vein. It usually is painful but if formed briskly enough can be absolutely unnoticed by the patient. The key symptoms of a DVT include; tightness in one of your calves, a swelling in one of your lower extremities associated by redness and warmth, and/or painful point specific areas in one calve that is worse with ambulation. If you suspect that you may have a DVT you need evaluation by a medically trained person to determine the extent or severity of the clot and the treatment needed. Basically, the further up the leg the symptoms extend the bigger the clot is as well as the potential for disaster. If you think you have a newly developed clot that is getting up to the level of your knee, then you need to take some action till you can reach qualified care. First, you need to be in a reclined position and elevate the affected leg which helps with the circulation. Also, remove or loosen any restricting or tight clothing. Finally, find some aspirin and take at least one 325 mg every 12 hours till you can be seen by a doctor. Further treatment of a DVT is highly individualized and beyond our scope here.

    The immediate danger with a DVT has nothing to do with your leg per se. Blood clots can be rather fragile and there is the potential for a piece of that clot to break off and travel through your circulatory system. Once a piece of clot is floating in your circulatory system it is known as an embolus. This embolus typically travels in your veins to and then through your heart. It ends up obstructing an artery in your lungs (Pulmonary Embolus aka PE). This PE in turn stops the blood flow to that portion of the lung. The cascade continues as the portion of your lung that is not receiving blood flow not only can’t help bring oxygen into your body anymore, that portion of lung can begin to die from a lack of blood flow (pulmonary infarction). In other words, the oxygen in that portion of the lung can not be transferred to the blood stream since there is no longer a blood stream in that section of lung. This explains why Paul’s airline patient was short of breath. With a PE, your breathing simply no longer exchanges CO2 and O2. If this occurs to large enough arteries you basically suffocate despite your ability to be able to breathe in and out. It has been estimated that up to 25% of untreated DVTs end up with a pulmonary embolus of different magnitudes. The key symptoms of a PE are: sudden chest pain, shortness of breath, increased heart rate and especially a cough that produces blood tinged sputum. Treatment of a PE is get to medical attention as this is a true emergency that is definitely life threatening.

    As mentioned above, this is a relatively common diagnosis. So much so, that prevention recommendations have been made by the airline industry. For example, South African Airline has ongoing rolling info-mercials on their individual entertainment screens at each seat which gives their clientele important preventative tips. However, don’t think for a moment that you have to be seated for hours and hours on a plane to get a DVT. Coastal US flights, and even 2 to 3 hours drives are enough to develop a DVT. Steve lost an aunt who died from a DVT/PE Christmas eve a few years back after a 2 1/2 hour drive home as a passenger after a family get together.

    Reduced risk of DVT can be accomplished with four steps. Number one is aerobic exercise that will significantly improve one’s cardiovascular system. Remember of course to check with your personal physician before starting a course of aerobic exercise. To be preventative, this must be an ongoing endeavor and not just before a trip.

    Number two is to keep the circulation of the lower extremities moving as much as possible while in transit. This can be accomplished easily in your seat by simply exercising your legs and feet every thirty minutes or so. Doing calve raises, alternating extending each lower leg and foot straight out and then back, making circular motions with each foot and alternating raising each thigh up and down will keep your blood moving in the right direction. You can also get up and stretch your legs every hour or so if your seat position and the pilot offer that opportunity on board a plane or by just taking a break by pulling over at rest stop while driving. Consider wearing over the counter compression stockings that can be found in your local pharmacy.

    Number three relates to your state of hydration. Increase your fluid intake, decrease or eliminate alcohol consumption (goes without saying when driving). Increased viscosity associated with dehydration is a risk of DVT formation.

    Number four are medications that act as blood thinners. The most commonly used and well known one is simple over-the-counter aspirin. Check with your doctor to find out if it is safe for you to take an adult 325 mg enteric coated aspirin a day for three to five days before your flight or long distance road trip. Aspirin acts by blocking the ability of platelets (cell fragments that are integral in the clotting process) from fully functioning, thus significantly reducing the potential for clot formation. There have been some medical studies published that recommended a much stronger and potentially dangerous prescription drug to be taken by all of those at even minimal risk for DVT. We have concerns that this may be more of a risk than a benefit because of the potential dangers that include massive bruising and profuse bleeding. Not a good idea for hunters going to remote rugged places.

    Prevention is the best course of action and, in this case, much easier then enduring the consequences.

    As always be safe and enjoy the outdoors.
    Last edited by a moderator: Dec 1, 2016

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